2010-06-04_PERMIT FILE - C1982056A (9)

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Excess non -clay material removed during lagoon construction was used to backfill the clay borrow area, and the topsoil was then re- spread and re- seeded using the approved seed mixture. The clay borrow area lies within a • Small Area Exemption previously approved under CYCC's C -81 -071 Permit. The SAE utilizes a rock check -dam and vegetative filters to control runoff and sediment, and is adequately sized to control the small amount of additional disturbance (approximately 0.8 acres, 4,000 CY of borrow material). See page 2.05 -81 for a description of the SAE. An influent pre- treatment structure was constructed on the influent line located upstream of the first treatment pond. The influent structure is of concrete construction with an inlet line, bar screen, flume, drying rack, and discharge structure. The inlet structure is approximately 18 feet long and 4 feet wide, and is constructed of reinforced concrete approximately 8 inches thick. To protect the influent structure, a building approximately V x 12 x 9 feet was constructed on a steel I -beam frame. This construction allows for removal of the building in the event maintenance to the influent structure is required. The wastewater flows through a buried 6 -inch PVC line into the pond. The pond influent line is anchored to an inlet /outlet apron located on the bottom of the pond. Each of the three treatment ponds have a set of inlet/outlet aprons. Six -inch PVC piping connects the ponds, and an overflow structure is located between each of the four ponds. The overflow structures each have a 6 -inch gate, and are of concrete construction. The effluent is chlorinated prior to 'discharge to the line to Site 114, and is discharged in accordance with applicable provisions of the CDPHE discharge permit. A control /chlorine contact building was constructed and contains control equipment for the aerators and a system which meters the appropriate amount of chlorine into the effluent. This building is approximately 16 x 12 x 9 feet and sets on a concrete pad. Power is supplied to the control building from the existing power distribution equipment at Site 114. Intermediate poles carry distribution lines from Site 114 to the building and aerators. All new poles incorporate approved raptor protection features. From Site 114, which is a spoil spring emanating from the reclaimed surface mine spoils, mixed flows of spoil is spring discharge and treated effluent can be pumped to the existing Million - Gallon Tank. The tank provides supplemental surface storage for the mine -water system. Water from the tank is pumped underground and used in the dust - control systems on the continuous miners and longwall shearer. A small percentage of the dust - control water is carried to the surface with the run -of -mine coal and shipped as surface moisture, while the remainder is diluted by mine water inflows and flows, or is pumped, to underground sumps. When the treatment facility is no longer needed it will be removed from the site. This will entail removal of the building, aerators, influent/pretreatment structure, and overflow structures. The remainder of the buried PVC will be left in place. The concrete pad for the building will be broken up and placed in the bottom of the ponds. The ponds will be backfilled and regraded with the overburden material to approximate original contours. The site will be topsoiled and reseeded with the approved mixture. The wastewater treatment facility is permitted through the Colorado Department of Public Health and Environment. The permitting process through the CDPHE required submittal of a site application. That application is presented in Exhibit 8 -0, Waste Water Treatment Facility. Also, the approval received from the CDPHE is included in the Exhibit. TCC did not include any of the technical segments of the application in effort to conserve map paper. Compressor Building (MR 03 -183) An air compressor building was constructed in the alley between the light duty bay and the shop. The location of the building is shown on Map 24, Surface Facilities. The building houses air compressors, dryer and controls, exhaust and tool storage area. The building was constructed by placing a roof over the alley and enclosing the front of the alley with a wall and doors. A borehole, approximately 150 feet in depth, was drilled from the alley into the underground workings. An airline was • installed in the borehole, which delivers compressed air to the underground equipment. The borehole was a nominal 10- inch boring and cased with a 6 -inch diameter aluminum tubing. The tubing was grouted in place and connections made at the top and bottom for completing the airline. MR09 -238 2.05 -20 06/26/09